The expansion of the Internet and the World Wide Web (“web”) has given computer users the enhanced ability to listen to and to watch various different forms of media through their computers. This media can be in the form of audio music, music videos, television programs, sporting events or any other form of audio or video media that a user wishes to watch or listen to.
Podcasting is a method of publishing digital media, typically audio programs, via the Internet, allowing users to subscribe to a feed of new files (e.g., .MP3s audio files). The word “podcasting” became popular in late 2004, largely due to automatic downloading of audio onto portable players or personal computers. Podcasting is distinct from other types of online media delivery because of its subscription model, which uses a “feed,” which may also be referred to as a “podcast,” to describe, identify and deliver an media file. A feed, in this context, refers to a list of files that can be easily interpreted to identify new files in the list as the files are added over time. Thus, one is said to subscribe to a feed because as new files are added to the list, the subscriber is notified of the new file and, in some cases, the new file is automatically delivered. The feed may exist as a discrete file, such as an .RSS file discussed below, or it may exist as part of a some other data format or element.
Podcasting enables independent producers to create self-published, syndicated media, such as “radio shows,” and gives broadcast news, radio, and television programs a new distribution method. Listeners may subscribe to feeds using “podcatching” software (a type of aggregator), which periodically checks for and downloads new content automatically. Most podcatching software enables the user to copy podcasts to portable music players. Most digital audio player or computer with audio-playing software can play podcasts. From the earliest RSS-enclosure tests, feeds have been used to deliver video files as well as audio. By 2005 some aggregators and mobile devices could receive and play video, but the “podcast” name remains most associated with audio. Other names are sometimes used for casting other forms of media, such as blogcasting for text and vcasting or vodcasting for video. For the purposes of this application, podcast is used in its most general sense to refer to a feed of new files in any format (e.g., .MP3, .MPEG, .WAV, .JPG) and containing any content (e.g., text-based, audible, visual or some combination) that can be subscribed to by a client. Also, for the purposes of this discussion an individual podcast may be referred to as a series, and each distinct new file in the series may be referred to as an individual episode of the series.
Podcasting is supported by underlying feed formats such as RSS. RSS is a family of XML file formats for web syndication used by (amongst other things) news websites and weblogs. The abbreviation is used to refer to the following standards: Rich Site Summary (RSS 0.91); RDF Site Summary (RSS 0.9 and 1.0); and Really Simple Syndication (RSS 2.0).
The technology behind RSS allows a client, in a client-server environment, to subscribe to RSS feeds on websites maintained by remote servers; these are typically sites that change or add content regularly. To use this technology the client needs some type of aggregation service or aggregator. The aggregator allows a client to subscribe to the podcasts that the client wants to get updates (i.e. future media files in the feed) on. Unlike typical subscriptions to pulp-based newspapers and magazines, your RSS subscriptions are free, but they typically only provide a line or two of each article or post along with a link to the full article or post.
The RSS formats provide web content or summaries of web content together with links to the full versions of the content, and other meta-data. This information is delivered as an XML file called RSS feed, webfeed, RSS stream, or RSS channel. In addition to facilitating syndication, RSS allows a website's frequent readers to track updates on the site using an aggregator.
RSS is widely used by the weblog community to share the latest episodes' headlines or their full text, and even attached multimedia files. In mid 2000, use of RSS for podcasting text spread to many major news organizations, including Reuters, CNN and the BBC, until under various usage agreements, providers allow other websites to incorporate their “syndicated” headline or headline-and-short-summary feeds. RSS is now used for many purposes, including marketing, bug-reports, or any other activity involving periodic updates or publications.
A program known as a feed reader or aggregator can check RSS-enabled webpages on behalf of a user and display any updated articles that it finds. It is now common to find RSS feeds on major web sites, as well as many smaller ones.
Client-side readers and aggregators are typically constructed as standalone programs or extensions to existing programs like web browsers. Such programs are available for various operating systems.
Podcasting has become a very popular and accepted media delivery paradigm. This success has caused the number and variety of podcasts available to clients to grow exponentially. Potential podcast consumers are now confronted with the problems of how to find podcasts, how to organize and manage their podcast subscriptions; and how to listen to episodes efficiently and easily. Podcast publishers are also confronted with problems including how to effectively market their podcasts, how to generate income from their podcasts, how to easily create and disseminate podcasts, how to support different feed formats and device needs, and how to manage bandwidth and storage costs.